An electric eel, ;, is a type of monster that appears in NetHack. It is an oviparous sea monster like its cousin, the giant eel. Electric eels have a touch attack that can result in a potential drowning instadeath if you are near any pool of water, as well as a shocking bite attack that can destroy wands and rings.
Electric eels are not randomly generated, but are a common sight in swamp rooms.
Electric eels are especially concerning when crossing large bodies of water: in addition to drowning you normally like giant eels and kraken, their shocking bite can destroy a ring of levitation, which can instantly drown you if it happens over water. As with other sea monsters, dispatch electric eels at a range outside of their reach to minimize danger, and use any monster-locating method (e.g., telepathy or warning) to make sure none of them get the jump on you.
The usual safeguards against drowning attacks apply, e.g., a non-cursed oilskin cloak prevents grabbing, and a wand of teleportation can reliably warp them away even on non-teleport levels. You can also use any means of scaring monsters such as Elbereth, or initiate levitation via other sources like a potion or spell, to shake loose an eel that has wrapped around you. Electric eels are vulnerable to spells and wands since they lack an MR score, but their -3 AC makes this unreliable for dealing with one that is about to drown you.
Electric eels are most dangerous in the Plane of Water: you are all but forced into proximity to them and cannot engrave anything. Most methods of keeping them back are still viable, such as wands of teleportation and instruments like tooled horns, but the wand of cold and cone of cold spell are rendered unusable, as is the scroll of earth. Many players prefer to not take chances and instead use a blessed scroll of genocide to wipe out all ; right after entering the level.
Electric eel corpses are generally passed over as a source of shock resistance, since they must usually be retrieved from the water they were killed in. This is easiest to do in swamp rooms: you can use a wand of fire or other fire source to evaporate the pool and its surrounding waters into pits, or freeze the square and adjacent waters before digging out the corpse.
South-American fish (_Gymnotus electricus_), living in fresh water. Shaped like a serpent, it can grow up to 2 metres. This eel is known for its electrical organ which enables it to paralyse creatures up to the size of a horse.
[ Van Dale's Groot Woordenboek der Nederlandse Taal ]